Fwiw, I can understand why oliverae might be feeling excluded from her child's world by this. It can be a big step-change, when your child goes to school - you can go from knowing most of what they are doing during the day, to having very little idea of what happens.
And, speaking from experience, you know less and less as the years go by. You ask your junior school son what he did in school that day, and get a grunted 'nothing' - you know that's not true, but that's all the information you are getting! Unless you have a specific reason to go and talk to the teacher, you don't find out what they're up to at school until reports or Parents' Evening. Same goes for senior school.
Then they go off to university - and you may have no idea what they are doing for weeks on end. You may have the ds or dd who rings every week to chat about their life and their studies - I had to text ds1, a fortnight into his first term at University, to see if he was still alive! But I know it is part of letting go, letting him become independent. I do still miss not knowing what's going on in his life, but I accept that's where I am now.
And he's just graduated, and is applying for jobs - soon he will (fingers crossed) be working, and won't even be home in the vacations - he'll get a lot less holiday, and may well go other places, with other people, instead of coming home to his Mum! 

Ds2's just finishing his second year of university - he is much closer to home, so we see him more often (usually when he wants to come and do a huge load of washing in our machine, instead of having to pay to use the Hall's laundrette
), so I have had more contact with him - but I know I still don't know a lot about his day to day life. And ds3 is off to university in the autumn, so I will be in a complete state of ignorance - though, in some ways, maybe ignorance is bliss - I won't be lying awake wondering when he will come home after a night out - if there's a major problem he - or someone else - will ring! And the same went for the other two - the difference being that ds3 is more of a social animal, and it will feel odd when all three are out there doing stuff without telling me about it!